1. Field of Invention
This invention relates to the preparation of foams. More particularly, this invention relates to the production of polybenzimidazole foams.
2. Prior Art
Many polymeric materials have been used in forming foam in the prior art and there are virtually as many methods of foaming prior art polymers as there are polymers. One example of a prior art polymer which readily can be foamed is polystyrene. However, a major problem with prior art polymeric foams is their lack of heat resistance. While these foams exhibit good insulation properties and provide excellent media for packing of delicate articles, when these foams are subject to even moderately elevated temperatures, they will collapse and lose their insulation or packaging properties.
Accordingly, it is an object of this invention to produce foams which exhibit good insulation and packaging properties.
It is another object of this invention to produce polybenzimidazole based foams.
It is another object of the invention to produce foams which maintain their foamed structure even when subject to elevated temperatures.
These and other objects are obtained by preparing polybenzimidazole foams according to the process of the instant invention.